Fluid-conveying system



Sept. 3,v 1929. R. J. MccARTY, JR

FLUID CONVEYING SYSTEM Filed Oct. 28, 1926 -Iralza'zial' AUX ' Patented Sept. 3, 1929.

UNITED sTATEs' l 1,726,625. PATENT OFFICE;

"RICHARD J. MCCARTY, Ja., or BETHLEHEM, PENNSYLVANIA, AssIGNon ro- BETHLEHEM STEEL coifrrliNr.l

FLUID-CONVEYING SYSTEM.

Application led -October 28, 192 6. Serial No. 144,777.

' My invention relates to valves and par? ticularly to relief valves.

The .device embodying my invention is particularly useful in connection with auxiliary locomotives of the type illustrated and described in an. application for Letters Patent Serial #130,606, `filed by R. S. A.

Dougherty and John A. McGrrew under date of August 21, 1926. Said application relates to an auxiliary engine mounted intermediate the axles of a tender. The motive fluid for the auxiliary locomotive is supplied by the steam pipe that connects the main steam pipe of the main locomotive with the steam chest of the auxiliary locomotive. The motive fluid is controlled by a throttle valve operated from the engi` neers cab. As fully described in the aforementioned application'when the auxiliary locomotive is started, itis automatically placed in gear with a normally idle axle of the tender truck. When the auxilia desirable toallow low pressure steam to flow through the steam pipe and passout through the cylinder cocks to the atmosplere. This is particularly desirable in cold weather. Furthermore the lubrication of the engine is generally provided for by means of a hydrostatic lubricator locatedin the cab. This lubricator has two connections7 one of which is a steam pipe from theV locomotive boiler while the other is an oil feed pipe from the lubricator to the auxiliary steam line. When the auxiliary engine is not in operation. it is customary to have the valve controlling the lubricator steam supply open, allowing low pressure steam to flow to the auxiliary' steam' line. The engine is provided with automatic Vcylinder cocks which remain open until sufficient pressure builds up in the cylinders to close them. The low pressure steam for warming purposes, is not suicient to close the cylinder cockswith the result that the heater steam passes freely to the atmosphere provided the cylinder'cocks are not obstructed.

The auxiliary engine is designed so that the driving gears will automatically mesh with a normally idle axle ofthe truck when it receives steam at a suflicient pressure to turn it over. Such. pressure is usually about 15 lbs. per square inch and as various combinations of conditions may occur to raise en gine is not in operation it has been ound form of my relief. device;

the pressure of the heater steam,'such as leaky throttle valves or stuck or obstructed cylinder cocks, the engine may be caused to ,start .and the gears engage at high train speed or when the locomotive is running backward which might be detrimental to the auxiliary engine mechanism.

It is` the primary object of my invention to provide a relief device for, maintaining line an prevent the pressure from building up suiciently to accidentally turn. theengine over.

Another object of my invention is to provide a means to render said relief device ineffective when the throttle is opened and steam ata comparatively high pressure is allowed to pass to the engine to start same. Broadly stated, my invention comprises a conduit for conveying steam to the auxiliary engine having an outlet which per- 'mits the escape of steam, and a weighted lvalve which is exposed to the pressure of Fig. 3 is a side elevation' of the throttle valve housing shown in Fig. 1 somewhat enlarged, being partially in cross section to illustrate bypass around the valve.

Fig. It is a cross section somewhat enlarged showing the choke diaphragmin the mouth of the bypass shown in Fig. 3; and l Fig. 5 is' a modified form of relief device.

a low pressure within the auxiliary steam 65v Referring to the drawings: 10 indicates a 100 locomotive having a boiler of usual construction for generating steam and coupled to a tender 11.6 An auxiliary engine 12 is suspended intermediate the axles of the rear tender truck 13 and is adapted to be en- 105 vtrained with a normally idle axle of said truck in the manner set forth in the aforementioned application.l

4A steam line 14. conveys the steam from the main steam line 15 to the auxiliary enuo the inlet end ofthe bypass ipe 18. In order to restrict the passage of t e steamthrough the bypass pipe and furnish low pressure.V steam for heating purposes to the auxiliary 'engine the aperture 20 in the choke 19 is relatively small in diameter.

Under normal conditions, 4when the locomotive is'propelled forward -at high speeds the atmosphere.

. v to propel the locomotive with the aid of the or is reversed and the auxiliary engine is inactive and disengaged from the axle of the tender truck, it is the purpose of the bypass to supply low pressure steam to theauxil'iary engine to heat same, such steam passing out through the cylinder cocks` (not shown) t0 If, however, it is desired auxiliary engine, then, the vengineer cracksf the throttle valve 16 and materially increases the pressure of the steam passing to the engine, thereby blowing out all condensate,

which may have collected in the system, and automatically closing the cylinder cocks i-n a manner well known to the art. The pressure builds u lwithin the cylinders of the auxiliary engine, suliciently to turn sanie- Aover, thereby'causing it to be entrained with the driven axle of the tender, in a manner fully described in the aforementioned application.

If, however, dueto certain conditions such` vas leaky throttle valve or stuck or obstructed cylinder cock, the pressure within the system builds up suliiciently to turn over the auxiliary engine andY cause entrainmet ther of with. the tender axle, at a time when t e main locomotive is running at relatively high speeds or in reverse it would be detrimental to the auxiliary lengine mechanism. In order to anticipate such a condition I, provide a relief device 21 located in the auxiliary pi line intermediate the throttle valve and t e auxiliary engine. Referring A to Fig. 2 the steam line 14 is apertured as at 22 to provide an outlet. The Waperture is threaded to receive a valve housing 23 which isprovided with a valve seat 24 receptive of the check valve 25 contained in the housing. At its upper end the housing 23 is provided with an outlet kaperture '26. A` second outlet aperture 27 is proyided in the steam line 14 which .is threaded to.receive the valve housing 28. The latter is divided into two chambers 29 and 30 which lare separated by an apertured diaphragm 31. The Iupper chamber 29 -has an' inlet aperture 32' and laterally disposed outlet aperture 33. The inlet aperture 32 communicates withthe out- ,cao

let aperture 26 through the medium of the pipe 34 and is provided at itsopening at the interior of the housing 28 with a valve seat 35. The housing 28 contains a valve 36 comprising a valve plate portion 37 and a piston portion 38 connected together by a stem portion 39. The piston portion 38 has a close sliding fit in the chamber 30 andthe stem portion extends through the aperture in the diaphragm 31. The valve plate portion 37 is contained in the ,chamber 29 and is adapted to engage the seat 35 when the valve -36 is moved upwardly. rlfhe valve is constrained to its lower position by'means of a coil spring 39 interposed between the .piston portion 3 8 and the diaphragm 31.

The outlet aperture 33 is connected by means of the pipe 40 to the inlet 41 of the housing 42. The latter is provided with a valve seat 43 and an outlet aperture 44. A weight valve 45 is `slidably mounted within @the housing 42 and normally rests in its closed position on the valve seat 43 thereby closing the inlet aperture 41. The valve 45 constitutes a-relief valve and is weighted so as to maintain a predetermined pressure within the steam line 14.

AThe safety device described above operates as follows: Assuming that it is desired to maintain a pressure of 2 lbs. per square inch within the steam line 14 so as to provide low Vpressure heatersteam to the engine, the

valve 45 is Weighted accordingly. It' the pressure rises due to circumstances extraneous to normal operating conditions, then the steam'escapes past the check valve 25 and having a free passage tothe housing 42 lifts `the valve 45 and escapes to the Aatmosphere by way of the outlet aperture 44. The pressure within the system is thus reduced and danger of building up a pressure suiiicient to start `the engine 12 is eliminated.

When it is desired to start'the engine 12 for the vpurpose of propelling the locomotive, the engineer cracks the throttle valve'1`6 and allows steam to pass to the engine in suiiicient quantity to blow out the condensate through the cylinder cocks. As the engineer continues to open the throttle valve, this Causes a rush of steam to the engine where it meets with resistance, builds up a pressure within the steam line 14betWeen-said valve of the'engine, and automatically closes the cylinder cock in a manner Vwell known to the art. This increased pressure acts on the lower face of the piston portion 38 of the valve 36 by way of outlet aperturev 27 which opens into the lower end of chamber 29. I

and thus renders the valve 45 ineffective to allowathe escape of steam. VThis traps a pocket of steam vin theY spaceintermediate the .check valve and \the valve 36 which will condense, reduce. the pressure and cause the check valve 25 to raise.v This action restores the pressure and drains the condensate automatically. When the throttle valve is closed, to shut down the engine 12, vthe pressure in the steam line drops to substantially atmospheric pressure and the check valve 25 is pressed toits seat by the pressure on 49 opening into said upper chamber. Concentric with the upper chamber is a guide ring 50 which is supported by spaced ribs 51 extendinginwardly and radially from the wall of the housing 46.

The housing 46 is provided `with inlet and outlet apertures 52 and "53 respectively. Valve seats 54 and 55 are formed in the body of the housing concentric with said inlet and outlet apertures respectively. A valve member 56 is slidably mounted within the housing 46 and comprises a lower valve plate portion' 57, an upper'valve plate portion 58, a iston portion 59 and a stem portion 60 w ich connects the piston portion to the upper valve plate portion 58. The latter portion is adapted to coact with the valve seat and the lower valve plate portion 57 is adapted to coact with the valve seat 54. The piston portion 59 sli'dably fits withinthe bore of the guide ring 50. The valve 56 is urged to its lowermost position by `gravity and the valve plate 57 engages withthe seat 54, thus closing the outlet from the steam line 14. The valve 56 in its lowermost position constitutes a relief valve and is weighted so as to maintain a certain pressure ofstea'm within the steam line 14 for the purpose of heating the engine 12. When the pressure is raised above a certain amount,

by reason of a leaky throttle valve or other conditions extraneous to normal conditions, the valve 56 lifts-and allows steam to escape through the annular passage 62, formed between the ouide ring -50 and the inner wall of the housing 46, to the atmos here. When the throttle valve f6' is opene 'in order to start the engine, the rush of steam at considerable pressure and comparatively large volume through the narrow annular passage 62 would create a resistance at that 'point, build up a pressure below the piston portion 59 and cause the valve tc raise and force the upper valveplate' 58 in i contacty with the valve seat 55. This prevents the escape of steam from the steam line 14. When the -I throttle valve is closed, to stop the engine, the valve 56 drops back to its original pos1-` tion and then functions once more as a relief valve. In order to somewhat oppose the momentum of the valve 56 as it moves upwardly to engage the seat 55 and prevent hammering, I provide a cushioning device 63 Whirh is secured to the housing 46 in the line of travel of said valve. This device may be of any well known construction s uitable for the purpose. The cushioning device illustrated comprises, spring pressed abutment member 64 which yieldingly engages the upper end of the valve 56 in advance of its extreme uppermost position and thus cushions t-hey force with which it is moved into engagement with the seat 55.

From the foregoing description it will be oseen that I have devised a simple and novel relief device which operates automatically to maintain a low pressure in the steam line to an engine for heating purpose, and operates automatically to prevent the escape of the steam when motive fluid is supplied to the 'I claim as new and desire to secure by Letters Patent is: 4 1. In a fluid conveying system, a valve housing having inlet and outlet apertures, a

weighted valve within the housing in its closed position with respect to said outlet adapted to be moved to its open position when the fluid pressure within the system exceeds a certain amount, and a second weighted valve Within the housing in its open position with respect kto said outlet adapted to be moved to its closed position when pressure within the system reaches a predetermined amount.

2. In a Huid conveying system, a main conduit, a branch conduit having an outlet, a relief valve controlling said outlet, a check valve in said branch conduit, a valve housing having an inlet from said main conduit, and a valve within said housing adapted to be moved by the fluid pressure Within the main conduit` to prevent the passage of iuid through said branch conduit.

3. In a power plant, a generator for supplying steam under pressure, an engine, a condult for conveying steam from said gensteam pressure withqin said conduit upon the opening of said throttle valve to render said erator to said engine, a throttle valve` a bypass :for conveyingv low pressure steam to said conduit and to said engine, a relief valve having an opening communicating with saidl conduit Vto permit the escape of steam when the pressure Within said conduit exceeds a certain amount, and means-actuated by the relief valve ineiiective.' l

p 4.- In a' luidconveying system, 'a conduithaving a pair of outlet apertures, a valve housing having inlets communicating with said outletl apertures respectively and also provided with an outlet aperture, a Weighted valve within said housing, a -second valve housing having an inlet communicating with said outlet in the first mentioned valve housing and having an outlet, and' a weighted valve within the last mentioned housing normally closing the inlet of same.

5. In a iiuid. conveying system, a. conduit having a pair of outlet' apertures, a valve housing having inlet apertures communieating with said outlet apertures respectively and also provided with an outlet aperture, a weighted valve Within said housing having a piston portion and a valve plate portion, said portions being of different diameter whereby thevalve may be subject to difi'erential load imposed thereon by pressure within said conduit, said piston portion being mounted slidingly Within said housing, 'a' valve seat formed at one of said inlets to said housing receptive of said valve plate portion, a second valve housing having inlet and outlet apertures, the last mentioned inlet aperture communicating with the outlet aperture of the first mentioned housing and having a valve seat, and a Weighted valve within the second valve housing normally engaging the last mentioned valve seat.

6. In a Huid conveying system, a conduit having a pair of outlet apertures, a valvehousing having Aan outlet aperture and also havingl an inlet apertire communicatingwith one of said outlet apertures, a secondA valve housln having anv outlet aperture and also a pair o inlet apertures communicating with. an outlet `aperture of the conduit and4 the first mentioned valve4 housing respectively, a third valve housing having inlet and outletapertures, the last mentioned inlet aperture communicating with the outlet of .said second housing, valves slidably mounted in eachl of rthe aforementioned housings respctively, al valve seat formed at the inlet aperture of the irst mentioned housing 're-v yceptive of valve contained in that housing,

conduit to permit theuescape of said Huid,

and means disposed in an open position with respect to said outlet adapted to4 be moved `by a pressure of fluid higher than the aforementioned pressure to close said utlet.

'8. In combination with a locomotive main steam line, of' an auxiliary engine,and aux-l iliary steam line-communicating said auxiliary engine with said main steam line and having an loutlet to permit the escape of y steam, a throttle valve in said auxiliary l steam line, a oy-pass for supplying low pre's-.

sure steam to said auxiliary engine when said throttle valve is in its closed or partially closedposition, means closing the aforementioned outlet adapted to 'be moved to a-n open position' With respect to said outlet by apredetcrmined pressure ofthe fluid Within said conduit, and means disposed -in'an open' position with respect to said outlet adapted to .be moved by a pressure of Huid higher than the aforementioned pressure Vto close Isaid outlet.

In *testlmony whereof I hereunto affix my 4 signature. y

RICHARD J. MCCARTY, JR. 

